Über das Vorkommen von R-Plasmiden in Escherichia coli und koliformen Keimen aus Wasser und Abwasser Teil 1: Einführung und Bedeutung der übertragbaren Chemotherapeuti-karesistenz bei gramnegativen Keimen aus Wasser und Abwasser

Plasmids have been known for about 20 years. Meanwhile, there have been selected different species of bacteria, as Shigella, Salmonella, Gonococci and Haemophilusinfluenzae strains with a plasmid-infected resistance. The share of resistant microorganisms has increased due to the application of chemotherapeutic agents in the human and veterinary medicine and in the flora. As can be proved, the application of liquid manure on large areas and its frequently observed introduction of wastewater — also from hospitals — contribute to the distribution of the plasmids (resistance plasmids) in the environment.     

Untersuchungen zum Vorkommen von R+-Bakterien im Flußwasser

With colony numbers of 2 · 10⁴… 3 · 10⁵ and coliform contents of 2 · 10³… 1 · 1 · 10⁴ per ml, in the investigated river section 2.1% of colonies were resistant to tetracycline, 0.3% to chloramphenicol, 7.5% to kanamycin, 5.4% to trimethoprim, 12.7% to ampicillin and 0.14% to gentamycin. For the coliforms the resistances were 5.1% to tetracycline, 2.1% to chloramphenicol, 2.7% to kanamycin and 0.15% to gentamycin. There were isolated 63 different resistance types. Of the resistant Klebsiella strains 75% were resistant to three or more antibiotics. Of the coliform bacteria (Escherichia coli, Klebsiella, Enterobacter, Citrobacter) 31.6… 51.9% of the strains transferred their antibiotics-resistance to Escherichia coli K-12, for the antibiotics-resistant strains of Pseudomonas and Aeromonas a transfer of resistance was not observed at all.     

Reduzierung von Bakterien- und Coliphagen-Konzentrationen auf der Fließstrecke eines Klärwerksableiters

Reduction of the Concentration of Bacteria and Coliphages along the Flowing Stretch of a Treated Sewage Channel The efficiency of surface waters to eliminate E. coli, fecal streptococci, Salmonella spp., and coliphages was evaluated in a small river which receives treated wastewater and which is rich in submerged macrophytes. The study took place between April and December, 1994. Total colony count, BOD₅, O₂ concentration and water temperature were determined in the river as well. As the river does not receive additional water downwards along its 17.2 km course, dilution effects could be ruled out as the cause for the elimination of the microorganisms. The reduction is assumed to happen rather due to sedimentation, grazing, and adsorption to the submerged waterplants. Immediately after discharge of the wastewater, the river water contained about 10⁵ cfu/100 mL E. coli and 10⁴ cfu/100 mL fecal streptococci, about 1000 pfu/100 mL coliphages, and, as a rule, was positive for salmonella in 10 mL. The reduction of E. coli, fecal streptococci, salmonella, clostridia, and coliphages at the end of the course was 1 to 2 orders of magnitude. This reduction took place mainly within the first 4.7 km, a part in which, due to low flowing velocities, suspended solids settle down efficiently. Besides, at the end of this part the submerged waterplants are especially abundant. The reduction of suspended solids correlated positively with that of BOD₅, bacteria, and coliphages. The reduction of microorganisms was not sufficient to fulfill the requirements of the European Community guidelines for bathing waters and for surface waters used as drinking water source. The regenerating capacity of surface waters is not sufficient to eliminate pathogens from convenionally treated wastewater. Therefore, tertiary treatment is necessary to keep receiving waters reasonably free from pathogens.     

Kontamination mit coliformen Keimen durch Insektenlarven bei der Aufbereitung von Trinkwasser

Contamination of Drinking Water with Coliform Organisms by the Larves of Gnats in the Water Treatment Plant E. coli and coliform organisms are used to judge the microbial quality of drinking water. The presence of these organisms in water indicates that there is a risk for faecal oral transmitted pathogen organisms. E. coli shows the faecal contamination of men and warm blooded animals (mammalian and birds), coliform organisms may be excreted as well from cold blooded animals. The cold blooded animals normally don’t excrete pathogen organisms relevant for human beings. So coliform organisms don’t have such a high relevance for drinking water microbiology. In this paper an incident is presented with a contamination of drinking water with coliform organisms in the treatment plant by the larves of gnats. The larves of the gnats crawl into the treatment chamber via entrance for ventilation. The larves were kept back on the surface of the filters but they contaminated the water with coliform organisms.     

Eliminierung und Rückgewinnung von Metallionen aus Abwässern — eine Übersicht

The present state and the trends of the recovery of heavy metals from wastewaters are presented. The classical precipitation techniques are insatisfactory due to increases of solubility in the presence of impurity ions and/or complexing agents. At present, ion-exchange processes constitute the most frequently used method of metal recycling with an effective enrichment of metal ions. For the effective separation of metals from solutions of a low concentration the electrolytic reduction demands large electrode surface areas. In cells with fixed-bed or fluidized cathodes one can obtain specific electrode surface areas of some 10³ m²/m^m3. For the future, processes of extraction and especially membrane separation will gain in importance. In the past few years, a large number of highly selective metal extracting agents as well as the liquid membrane permeation with suitable carriers were developed. Combinations of membrane separation processes with chemical reactions may attain the same importance, as e.g. ultrafiltration in connection with the fixation of metal ions to watersoluble polymers. In the long run, especially techniques will prevail which will not only result in metal enrichment but also in the recovery of the raw material water.     

Untersuchungen zum Nachweis von Escherichia coli im Wasser

From river water there were isolated 21 species (mainly coliform bacteria) in 914 strains. Of the pure cultures of coliform bacteria (E. coli, Enterobacter, Klebsiella, Citrobacter) 74.1 % of E. coli and 23.2 % of the Klebsiella strains showed lactose decomposition with gas formation at 44 °C. More than 90 % of the isolated Klebsiella did not form indole. Therefore, the temperature test and the indole formation (at 44 °C) (TI-test) made a very specific detection of E. coli in water possible. 94.7 % of the cultures grown initially on endoagar after a positive TI-test proved to be E. coli. The detection of E. coli showed a very good agreement with the standard method and the TI-test, the detection with the standard method being considerably dependent on the number of checked coliform colonies.     

Mehrjährige Ergebnisse über den Einfluß von Hochbelastungen mit künstlich-biologisch gereinigten kommunalem Abwasser auf die Sickerwasserbeschaffenheit

Biologically purified wastewater in ten doses of 50 and 400 mm per year was given into sand-filled lysimeters of 1 m² area and 1 m depth which were vegetated with Lolium perenne (forage rye) and green maize all the year round. The experimental results gained in the course of five summer half-years and four winter half-years were evaluated with respect to the purification efficiency of the soil-plant system. The results demonstrate a high efficiency of the system with mean annual elimination performances of 86 and 40% for BOD₅, and COD-Cr, resp., as well as 49, 86 and 52% for N, P and K, resp., at mean concentrations in mg/l for BOD₅?1.3, COD-Cr?34.1, N?18.1, P?0.4 and K?9 in the percolating water from a soil depth of 1 m. The lysimeters which had been supplied with wastewater were not treated with mineral fertilizer. Intermingling with 1 kg/m² straw brings about an increase of the loads of K and P as well as COD-Cr in the percolating water and a reduction of the N-loads, besides an increase in yield. All in all, for four years the performance has been stable without any temporal trend.     

Zur Frage der Einleutung von gereinigtem Abwasser in Seen

Zusammenfassung Ein Vergleich der aktuellen Phosphorzufuhr mit der tolerierbaren Belastung der Seen zeigt, dass allein die aus B?den aus- und abgeschwemmte Phosphormenge genügt, um selbst die grossen Alpenrandseen zu gef?hrden. Es ist daher dringend erforderlich, die dritte Reinigungsstufe nicht nur in den Kl?ranlagen der Ufergemeinden, sondern im ganzen Einzugsgebiet einzuführen. Kommunales Abwasser enth?lt auch nach der Phosphatelimination noch soviel Phosphor, dass es zumindest lokal eine beachtliche Prim?rproduktion in Gang zu halten vermag. Es wurde daher untersucht, in welcher Tiefe sich im See das gereinigte Abwasser einschichten müsse, damit es keine direkt düngende Wirkung mehr habe. Es zeigte sich, dass eine solche w?hrend der Sommerstagnation mit grosser Wahrscheinlichkeit ausgeschlossen werden kann, wenn sich das gereinigte Abwasser, ohne die trophogene Schicht zu passieren, unterhalb jener Tiefe einschichtet, in der noch 5% der Oberfl?chenintensit?tI _o des am tiefsten eindringenden Spektralbereichs gemessen werden. Da exakte optische Untersuchungen bis jetzt nur an relativ menigen Seen durchgeführt wurden, versuchten wir eine Beziehung zwischen der erforderlichen Einschichtungstiefe und der Sichttiefe zu finden. Die erarbeiteten Richtwerte wurden in einem angenommenen praktischen Beispiel angewendet. Summary A comparison between the actual influx of phosphorus and the maximum load a lake can tolerate shows that the phosphorus run-off from the soil suffices to endanger even the large lakes at the foot of the Alps. It is therefore an absolute necessity that the treatment for phosphate removal be introduced not only in wastewater purification plants along the shores of lakes but also in those in the entire catchment area. Even after phosphate precipitation, municipal wastewater still contains so much phosphorus that it can sustain considerable primary production, at least locally. An attempt was made to determine at which depth in the lake the purified wastewater no longer had any direct stimulating effect on plant growth. It was found that growth can most probably be impeded during summer stagnation if the purified wastewater is discharged not on top of the trophogenic layer, but be introduced at a particular depth. This depth is characterized by the fact that only 5% of the surface intensityI _o of the deepest penetrating rays can still be measured. Since exact optical examinations were carried out in relatively few lakes, we strove to establish a correlation between the required stratification depth and transparency by secchi disk. The general values obtained were applied to a hypothetical practical example.      

Untersuchung der Sorptionseigenschaften des Kationenaustauschers KB-2M mit Makronetzstruktur zur Abtrennung von Zinkionen aus Ab- und Spülwässern

Study of Sorptional Properties of the Cation Exchanger KB-2M with Macroreticular Structure for Recovery of Zinc Ions from Sewage and Rinsing Water Although a number of ion-exchange methods have been employed for the recovery of some transition metals from industrial effluents, knowledge about ion-exchange resins with macroreticular structure is poor. The present paper describes the mechanism of sorption on such exchangers and their application for recovery of zinc from sewage rinsing water. Ion exchanger of macroreticular structure are polymers with long-chained cross-linking agents. We have synthesized carboxylic ion-exchange resins by hydrolysis of copolymerisates of methyl acrylate with different cross-linking agents: divinylbenzene, divinyl sulfide, divinyl ester of ethylene glycol and divinyl ester of di- or triethylene glycol. The sorption process on modifications of the carboxylic resins KB-2 of various structure was studied with different methods: potentiometric titration, infrared spectroscopy, electron microscopy, X-ray structural analysis. The initial zinc concentration in rinsing water was 0.05 mol/L at pH from 3 to 6. For the sorption, 0.2…1.0 g of resin were equilibrated with 100 mL of zinc solution. After equilibrium (12 h), the resin was separated from solution. The zinc ions were determined by atomic absorption spectrometry after stripping with 100 mL of 10% sulfuric acid. The distribution ratio D was calculated (D: mmole of Zn sorbed per gram of resin divided by mmole of Zn per millilitre of solution). By means of infrared spectroscopy, the mechanism of sorption of zinc ions from rinsing water was determined. There may be a possibility of the formation of complexes in the cation-exchange resin phase. It was found out in this paper that the cation-exchanger KB-2M of macroreticular structure is the most effective for the sorption of the Zn²⁺-ions from sewage and rinsing water.     

Surveillance of Invasive Bacterial Pathogens and Human Enteric Viruses in Wastewater Final Effluents and Receiving Water Bodies – a Case Study from Durban,South Africa

The physico‐chemical characteristics and microbial composition of the final effluents of two municipal wastewater treatment plants in South Africa were assessed between July and September 2009. The impact of the treated final effluents on the receiving water bodies was also evaluated. The temperature across all sampling points ranged between 14 and 22°C, while pH varied from 6.9 to 7.6. High levels of turbidity, chemical oxygen demand (COD), ammonia, nitrate, nitrite and orthophosphate (PO₄) were observed in many cases. Turbidity of the samples was in the range of 2.2–288.6 NTU. The concentrations (mg/L) of other physico‐chemical parameters are as follows: COD (9.33–289); ammonia (0.000340–45.4); nitrate (0.062–539); nitrite (0.021–22.6); PO₄ (5.3–33.2). The microbial quality of the effluents discharged from the plants did not comply with the limits set by the South African guidelines with respect to pathogens such as Salmonella, Shigella, Escherichia coli, total coliform, faecal coliform, enterococci, faecal streptococci, and viral particles for effluents intended for discharge into receiving watersheds. This study revealed an undesirable impact on the physico‐chemical and microbial qualities of the receiving water bodies as a result of the discharge of inadequately treated effluents from the wastewater treatment facilities. This poses a health risk to several rural communities which rely on the receiving water bodies primarily as their sources of domestic water and recreational purposes. There is therefore a need for the intervention of appropriate regulatory agencies in South Africa to ensure compliance of treatment facilities with wastewater effluent quality standards.     

Die Einleitung von gereinigtem Abwasser in Seen

Treated wastewater discharged into a lake should be introduced below the trophogenic layer. Tracing the marked wastewater by echosounding revealed that the usual discharge method is unsuitable. The wastewater flows more or less to the depth of its own density, which is usually in the trophogenic layer. If there is no movement, that is, current in the water body, the wastewater accumulates at the pipe's mouth. A continuous current is therefore an indispensable prerequisite for a wastewater discharge site. It is only when wastewater is mixed with at least five parts of lake water that it does not rise more than two meters.     

Hygienische Aspekte der Trinkwassergewinnung aus Uferfiltration und Grundwasseranreicherung

Today, bank filtration and artificial recharge of groundwater are two important process steps of the obtaining of drinking water, in view of the fact that the pollution of surface waters has considerably increased. If surface waters are highly polluted, in many cases a preliminary treatment is necessary. To provide protection from heavy bacterial contamination, it is recommended to orientate towards a bottom passage of the infiltrating surface water of at least 100 days. Under favourable conditions, the periods of survival are 100 days for E. coli, 100 days for Salmonella typhii, up to 200 days for Yersinia, and up to 250 days for polioviruses. A high quality of the drinking water obtained from bank-filtrated and infiltrated water is secured by protection of waters from pollutions in their catchment areas and by a drinking water treatment meeting all hygienic demands.     

Möglichkeiten der Nachreinigung von Abwässern aus der Kunstlederproduktion mit Hilfe von Algen,Teil 2

The attempt was made to use the alga Scenedesmus quadricauda for the purification of wastewaters from the production of artificial leather. The dimethylamine contained in these wastewaters is continuously decomposed and the remaining nitrogen-containing residuals are used as a nutrient source for the production of algal biomass. In continuous experiments with original wastewaters, dimethylamine and its metabolites showed a pronounced inhibiting effect. In practice, a longer retention time in the reactors as well as a sufficient share of municipal wastewater are required in order to avoid a limiting of growth due to a phosphorus deficiency. The second part of this paper is concluded by information about other investigations performed by us on the purification of artificial leather wastewaters with the aid of the biological nitrogen elimination under specific conditions with a successful denitrification of up to 95%.     

Stand und Entwicklungstendenzen der biologischen Phosphatelimination aus Abwasser mit Belebtschlamm

The recovery of phosphorus will become almost as important as its removal for preventing eutrophication. In this connection, the biological techniques for the elimination of P are of a special importance. The fundamentals and the process technologies of the “phostrip” technique and the anaerobic/aerobic technique are described. The biological P-removal is more susceptible to interference than the normal activated sludge process is. The most important sources of troubles are discussed. For a stable process it is necessary at the anaerobic stage that neither molecular oxygen nor nitrate oxygen are present and that the organic substances contained in the waste water are partly hydrolyzed in order to use up the intracellular energy reserves in the form of polyphosphates to a considerable degree. Moreover, at the aerobic stage there have to be guaranteed high rates of growth of the P-storing bacteria and the formation of polyphosphates as well as only a low degree of nitrification. From this results an increased expenditure for the process control especially for the oxygen and nitrate concentrations at the aerobic stage. The results from two model plants are represented.     

Untersuchung der Anwendungsmöglichkeiten von einigen komplexbildenden Ionenaustauschern zur Kupferabtrennung aus natürlichen Wässern und Abwässern

Application of Some Complexing Ion Exchangers for Copper Recovery from Natural Water and Wastewater The rational use of water resources is one of the urgent environmental control problems. These problems can be solved by the treatment of sewage. Removal of different non‐ferrous heavy metal ions from wastewater is of great importance. Besides, the selective complexing ion exchangers are of interest because of their good sorption properties. The present paper is devoted to the study of some complexing resins for copper recovery from natural water and sewage. The following carboxylic resins were studied: the cation exchangers KB‐2T, KB‐4 and the amphoteric ion exchangers ANKB 35, AMF‐2T, and AMF‐2S (manufacturer – “TOKEM” company, Kemerovo, Russia). The exchangers investigated differed from each other both by their functional groups and by their matrix physical structures. The copper recovery from CuCl₂‐, CuSO₄‐, and Cu(NO₃)₂‐solutions was studied in batch‐experiments (in presence of NaCl, Na₂SO₄, and NaNO₃). The initial copper concentration in the solutions was 0.0002...0.008 mol/L; pH values were 1.0...5.0. After equilibrium (24 h) the resins were separated from the solution. The copper concentration in the solutions after the sorption was determined by the photometrical method with pyridylazoresorcin (λ = 500 nm). On the basis of the experimental data distribution ratio, the separation factors, equilibrium constants, and stability constants of copper complexes in the exchanger phase were calculated. It was found out in this work that the amphoteric ion exchanger AMF‐2T of macroreticular structure is the most effective for the copper sorption from sewage.     

Die Massenentwicklung der Geißelalge Uroglena americana (Alk.) Lemm in Trinkwassertalsperren Thüringens und ihre Bekämpfung

A mass development of Uroglena americana with cellular densities of up to 13.5 · 10⁶ and 86.10⁶ cells/l, was observed in two drinking-water reservoirs. In the first case the development remained confined to the upper 20 m, in the second case there occurred a gradual shift of the maximum to deeper zones from May to July with decreasing cellular densities down to a depth of 35 m. Laboratory experiments for the control of the algae development were performed in order to protect the drinking-water resources from potential impairments of odour and taste. Samples of the storage-reservoir water with 20.10⁶ cells/l of Uroglena were concentrated up to 1.25 … 12.5 mg/l Ca(OH)₂ (pH-values of 7.2 … 9.6) by addition of calcium hydroxide and observed for 39 h. First impairment of the cells of Uroglena is detectable at 5 mg/l Ca(OH)₂ after 15 h, an immediate effect can be observed at 7.5 mg/l Ca(OH)₂ together with increased sedimentation, also Gymnodinium and Cryptomonas having been damaged. Thereupon a successful control of Uroglena by liming up to pH-values above 8.0 is possible. The application of lime to outdoor areas was not necessary, in the final analysis, since the drinking-water quality could be secured by the optimum choice of the intake depth of raw water with a maximum of 4.10³ to 77.10³ cells/l.     

Anwendung von biologischen Testverfahren an Abwässern der Textilindustrie

Testing Effluents of the Textile Refining Industry with Biological Methods The environmental problems caused by the manufacture of finished textiles involve a long chain of individual processes. This “textile chain” includes very diverse enterprises of varied size and structure. The textile refiners occupy a key position in the “textile chain”. On the one hand, this is due to their use of an obscurely large number of chemicals which can end up in the wastewater as well as in the textile products. On the other hand, this key role of the textile refining industry is based on their central position between the preproduction stage and the consumers. This study dealt with the textile refining industry's wastewater. As measured by volume and contents of its wastewater, this industry can be counted among the major industrial plants which discharge into municipal wastewater treatment plants. German wastewater legislation includes the provision that substances which are toxic, persistent, capable of accumulating, carcinogenic, fetotoxic or mutagenic be kept out of natural waters as well as technically possible (Wasserhaushaltsgesetz WHG). Several biotest methods for examining the effect of the substances contained in the wastewater were incorporated into the appendix of the German wastewater regulation (Rahmenabwasser-Verwaltungsvorschrift based on § 7a WHG). The aim of this study was to show, with the aid of biotest methods, how strongly the wastewater of textile refining companies is polluted as compared to other known industrial branches and to what degree the pollution of these wastewaters is eliminated by the treatment in wastewater treatment plants. Finally, we experimented to find out which biotest methods were suited for the examination of these wastewaters. The study's results show that the ecotoxicity of the textile refining industry's wastewater was only extraordinary high in isolated cases as compared to other examined branches of industry. The textile wastewaters exhibit values of G_L = 3 to G_L = 96 in the luminescent bacteria test, G_D = 1 to G_D = 192 (with one exception of G_D > 30000) in the daphnia test and G_F < = 2 to G_F = 32 in the fish test. It turned out though, that a large number of the samples from the textile refining companies (27%) reacted mutagenically in the Ames test in their native state. Consecutive tests for chromosomal aberrations (V79 hamster cell test) also showed mutagenic potential in five out of nine native samples. The employed testing methods with fish, daphnia and luminescent bacteria demonstrate a higher sensitivity of the luminescent bacteria and/or the daphnia as opposed to the fish in most cases. As the fish test is controversial anyway on the grounds of animal protection, a replacement of the fish test by these other tests should be aimed at: on account of the different end points of the luminescent bacteria and the daphnia test, a combination of these tests appears most sensible.     

Nitrifikation – Grundlagen des Stoffwechsels und Probleme bei der Nutzung von Ammoniakoxidanten

Nitrification – Fundamentals of the Metabolism and Problems at the Use of Ammonia Oxidizers From an ecological point of view, a great problem results from the release of increasing amounts of inorganic and organic nitrogen compounds. Apart from gaseous nitrogen compounds, such as the greenhouse gas N₂O, soluble nitrogen compounds such as ammonium cause difficulties. In recent years, great progress has been made regarding the reduction of the emission of sulfur and phosphorus compounds. Since there are no effective strategies for the decrease of nitrogen releases, the emission of such compounds has even been increasing. Therefore, great efforts are being made to eliminate the soluble nitrogen compounds in particular, for example in wastewater treatment plants. A decisive meaning befits the chemolithoautotrophic ammonia oxidizers. This review focuses on the ecological consequences of the release of ammonia in particular, the metabolism of the ammonia oxidizing microorganisms under consideration of the latest research results, and the problems that arise in the context of using these bacteria for the removal of ammonia.     

Untersuchung von drei Grundwasserwerken auf Vorkommen von Acanthamoeben,Naeglerien und anderen freilebenden Amöben

Prevalence of Acanthamoebae, Naegleriae and Other Free-living Amoebae in the Course of Water Treatment in Three Well Waterworks Numerous species of free-living amoebae and other protozoa had been observed in the raw water of three representative waterworks with enriched well water. They were eliminated most effectively during the water treatment procedure. Acanthamoebae and Naegleriae including thermophilic strains of these genera could not be identified in any of the clear water samples. Acanthamoebae and Vannellae isolated from different samples exhibited repeatedly intracellular infections with bacteria of the genus Cytophaga. Their role as possible hosts of different pathogenic and non pathogenic bacteria like Legionella sp., Listeria sp., and Pseudomonas sp. is confirmed by this observation. As known from earlier findings in connection with the Acanthamoeba-Legionella model, it can be assumed, that bacteria multiplying in trophozoites or being enclosed in cysts are protected against high concentrations of chlorine and other biocides.